Preheat the oven to 400 F if using the oven method- I air-fried my chicken on 375 F.
Prepare the pickled or sumac onions to let them marinate while you prep the rest of the meal.
Cut each chicken breast in half and then into strips, about 3u0022 long. Add it to a bowl with a drizzle of olive oil and the spices. Toss together to combine.
Add the chicken to your air-fryer rack and air-fry on 375 F for 12-15 minutes, flipping halfway through. If baking, add the chicken to a sheet-pan and bake on 400 F for 15 minutes, flipping halfway through. Broil for 1-2 minutes at the end.
While that bakes, prepare the harissa mayo sauce by whisking or blending together the mayo, harissa, chopped parsley, lemon juice, and spices until smooth.
Once the chicken is ready, heat your tortillas over a flame or on a heated pan. Spread the harissa mayo over the center and layer with the lettuce, spiced chicken, avocado and onions. Fold in both sides then wrap using parchment paper to hold it together